One day Nasrudin bumped into another man, sending them both to the ground.
“Oh, excuse me,” Nasrudin said. “Are you me, or am I you?”
“I am me,” the man said, “and as for you, you must be some kind of psycho, asking me such a question.”
“Oh, I am no psycho,” replied Nasrudin. “It’s just that we look similar, and when we bumped into each other and fell, I thought we might have gotten mixed up in the fall.”